Module: Create Grid System
Copyrights (c) 2007 by Volker Wichmann
Menu: Grid > Tools > Construction
Description
This module creates a new user specified Grid System for use with other modules.

First of all, please consider the following issues before using the module:
(a) all calculations of the module refer to the lower left corner of the grid system, i.e. the xMin and yMin values. This coordinate is fixed unless you specify an offset.
(b) the module follows the philosophy of SAGA in that the values describing the extent refer to the cell centers. If you like to match the extent with the border of a grid, use an offset.

The module provides four possibilities to set/determine the extent of the grid system:
(1) by specifying the coordinate of the lower left cell (xMin, yMin) and the number of cells in W-E (NX) and S-N (NY) direction
(2) by specifying the coordinates the of lower left (xMin, yMin) and the upper right (xMax, yMax) cell
(3) by the extent of the shape(s) provided in the Data Objects section
(4) by the extent of the grid(s) provided in the Data Objects section

After selecting the appropriate method to determine the extent, the next step is to specify the cellsize of the new grid system.
For all methods supplied to determine the extent but number (1), three possibilities are provided to adjust cellsize and grid system extent (please remember, the lower left corner is fixed!):
(I) adjust the extent to match the cellsize
(II) adjust the cellsize to match the extent in E-W direction
(III) adjust the cellsize to match the extent in S-N direction

Finally it is possible to apply an offset to the lower left corner of the grid system. In this case check the Use Offset option and specify the offset in W-E and S-N direction. Positive values result in a shift in E/N, negative in W/S direction.
In order to create the grid system the module needs to create a dummy grid.
Parameters
NameTypeIdentifierDescriptionConstraints
Input
Shape(s) (*)Shapes list (optional input)SHAPESLISTShape(s) to fit extent to
Grid(s) (*)Grid list (optional input)GRIDLISTGrid(s) to fit extent to
Output
Dummy Grid (*)Data Object (optional output)GRID
Options
Set extent byChoiceM_EXTENTPlease choose a method of module operation.Available Choices:
[0] xMin, yMin, NX, NY
[1] xMin, yMin, xMax, yMax
[2] Shape(s)
[3] Grid(s)
xMinFloating pointXMINminimum x value
yMinFloating pointYMINminimum y value
xMaxFloating pointXMAXmaximum x value
yMaxFloating pointYMAXmaximum y value
NXIntegerNXnumber of cells in W-E directionMinimum: 1.000000
NYIntegerNYnumber of cells in S-N directionMinimum: 1.000000
CellsizeFloating pointCELLSIZECellsizeMinimum: 0.000000
AdjustChoiceADJUSTChoose method how to adjust input values.Available Choices:
[0] Extent to CellSize
[1] CellSize to W-E Extent
[2] CellSize to S-N Extent
Use OffsetBooleanUSEOFFApply offset?
X offsetFloating pointXOFFSETPositive values result in a shift in E direction.
Y offsetFloating pointYOFFSETPositive values result in a shift in N direction.
(*) optional